As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
As processors, graphics cards, random access memory (RAM) and other components in information handling systems have increased in clock speed and power consumption, the amount of heat produced by such components as a side-effect of normal operation has also increased. Often, the temperatures of these components need to be kept within a reasonable range to prevent overheating, instability, malfunction, and damage leading to a shortened component lifespan. Accordingly, heatsinks and/or air movers (e.g., cooling fans and blowers) have often been used in information handling systems to cool information handling systems and their components.
Various challenges may arise in the cooling context based on the airflow impedances of information handling resources. Airflow impedance, typically defined as the ratio of pressure to airflow, describes how much resistance to flow a particular configuration of components (e.g., an expansion card, a physical storage resource such as a hard drive, or a module including multiple types of components) presents.
In particular, when devices with a shared airflow path have heterogeneous impedances, additional difficulties can arise. For example, when one or more air movers are providing airflow to several modules along a shared airflow path, an unequal distribution of that airflow typically results. Those modules with high impedance may not receive sufficient airflow, and those with low impedance may receive more airflow than necessary.
Existing solutions have sometimes relied on “worst-case” impedance calculations to ensure that even those modules with high airflow impedance receive sufficient airflow. This may be considered wasteful, however, in terms of the number of air movers required and the power consumed thereby. The additional power consumption of such air movers is of course an extra source of heat, further exacerbating the problem. Other existing solutions have sometimes relied on average impedances, but such solutions are also suboptimal because they fail to capture important characteristics of the system.
This disclosure thus provides improved techniques for cooling, such that the various airflow impedances of the modules that need to be cooled are taken into account without simply assuming a worst-case or average-case scenario. Techniques according to this disclosure may be particularly applicable in the open-loop control context, although they need not be so limited.
It should be noted that the discussion of a technique in the Background section of this disclosure does not constitute an admission of prior-art status. No such admissions are made herein, unless clearly and unambiguously identified as such.